As this kind of machining system, a machining system which is configured so that prefetched movement data of a machine tool obtained by prefetching a machining program of a numerical controller and carrying out an interpolation calculation on the machining program, and status data of a robot recognized by a robot controller are sent to an interference checking device, and interference between the machine tool and the robot is checked by the interference checking device is known. (See PTL 1, for example.)
Also, a machining system which includes a numerical controller having an internal clock, a robot controller having an internal clock, and a reference clock, and which synchronizes the machine tool to the robot is also known. (See PTL 2, for example.) With this machining system, the numerical controller and the robot controller are configured to operate so that the time of their internal clocks respectively correspond to that of the reference clock, and on the other hand, the numerical controller and the robot controller are configured to adjust the time of the reference clock so as to correspond to that of their internal clocks when the time of the internal clocks thereof failed to correspond to that of the reference clock.